A mini-stroke may not cause lasting physical damage, but it could increase your risk of developing post-traumatic stress disorder (PTSD), a small, new study suggests.

Almost one-third of patients who suffered a mini-stroke -- known as a transient ischemic attack (TIA) -- developed symptoms of PTSD, including depression, anxiety and reduced quality of life, the researchers said.

"At the moment, a TIA is seen by doctors as a fairly benign disorder," said study co-author Kathrin Utz, a researcher in the department of neurology at the University of Erlangen-Nuremberg in Germany.

However, Utz and colleagues found that from a patient's perspective, a TIA is not so benign.

"We found one in three patients develop PTSD, which is perhaps better known as a problem found in survivors of war zones and natural disasters," Utz said.

PTSD can develop when a person experiences a frightening event that poses a serious threat, she explained. "It leads the person to experience symptoms such as worry, nightmares, flashbacks and social isolation," she said.

The findings are based on questionnaires completed by 108 study volunteers three months after having a TIA. The responses also revealed that about 14 percent had significantly reduced mental quality of life after their mini-stroke, and 6.5 percent had reduced physical quality of life.

The participants' median age was 70, according to the study, published Oct. 2 online in the journal Stroke.

TIA is a fairly common neurological condition. Five out of 1,000 people will experience one at some point during their life, Utz said. Like stroke, transient ischemic attacks are caused by restricted blood supply to the brain.

"TIAs are brief episodes of stroke-like symptoms, such as sudden onset of numbness, weakness or paralysis, slurred speech, loss of language, sudden loss of memory, blurred vision, confusion, and severe headache," Utz said. "However, in contrast to a stroke, no residual impairment remains."

TIAs are considered to be a warning sign for a stroke. It is important that patients who experience one of these mini-strokes see their doctor, Utz said.

It's not entirely clear why some patients develop post-traumatic stress disorder following a TIA, but others do not, she said.

"However, what we do know at this stage is that younger patients and patients who in general find it difficult to cope with stress are more likely to develop psychological problems following a TIA," Utz said.

"We also found that patients who overestimate their risk of suffering a future stroke are also more likely to show psychological problems," she added.